The present invention relates to a head gimbals assembly and a head stack assembly for a magnetic disk drive and, more particularly, to a head gimbal assembly and a head stack assembly having accurate dimensions after its fabrication and suitable for use on a compact magnetic disk drive.
Various types of portable recording media are provided for various devices including personal computers (PCS) and digital cameras to store data. Efforts have been made in recent years to provide recording media having a small size and a large storage capacity. For example, a small, portable magnetic disk drive has been proposed. This proposed disk drive has a new assembly construction based on the Compact Flash® commercially available from SanDisk Corporation, i.e., one of standards for small memory cards.
A large-capacity miniature magnetic disk drive conforming to the standard of Compact Flash Type 2 is provided with a 1 in. diameter magnetic disk having a storage capacity of 1 GB, and has a weight on the order of only 16 g.
This portable, miniature magnetic disk drive comprises, in addition to a magnetic disk for data storage, a spindle motor for rotating the magnetic disk, a magnetic head for writing data to and reading data from the magnetic disk, a suspension assembly suspending the magnetic head, and an actuator supporting the suspension assembly to move the magnetic head in a direction along the radius of the magnetic disk.
In the progressively miniaturized magnetic disk drive, the suspension supporting the magnetic head as a mechanical component is required to be formed in a high dimensional accuracy. A suspension assembly proposed by Japanese Patent Laid-open No. 2001-155458 (p. 3, FIG. 2), includes a load beam consisting of a plate spring, i.e., an elastic member, and a beam, to reduce the influence of disturbing wind. A suspension assembly disclosed in U.S. Pat. No. 6,381,099 (Specification, cols. 3 and 4, FIG. 1) has a load beam consisting of a base part, a rigid part and an elastic part connecting the base part and the rigid part.
Efforts have been made for the further capacity enhancement and miniaturization of the portable miniature magnetic disk drive to be loaded into a portable device, and the pivot of the head stack assembly, the carriage assembly and the head gimbal assembly must be assembled in high dimensional accuracy. There are difficulties in managing the alignment of the head stack assembly of the miniature magnetic disk drive in conformity to design values. The component parts are unable to exercise satisfactory functions because severe limits are set for design regions for the component parts, the component parts must be carefully handled in assembling the same because the component parts are liable to be damaged. The lightweight head stack assembly included in the miniature magnetic disk drive operates unstably and is unable to function properly unless the alignment of the component parts is managed. Conventional techniques including techniques disclosed in the references above do not deal with the improvement of the accuracy of the alignment of the head stack assembly when it is assembled, which is a lightweight component.